package com.qinlong275.android.photogallery;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Message;
import android.util.Log;
import android.view.animation.OvershootInterpolator;

import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * Created by 秦龙 on 2017/9/28.
 */

public class ThumbnailDownloader <T> extends HandlerThread {

    private static final String TAG="ThumbnailDownloader";
    private static final int MESSAGE_DOWNLOAD=0;
    private boolean mHasQuit=false;
    private Handler mRequestHandler;
    private ConcurrentMap<T,String> mRequestMap=new ConcurrentHashMap<>();
    private Handler mResponseHandler;
    private ThumbnailDownloadListener<T> mThumbnailDownloadListener;

    public interface ThumbnailDownloadListener<T>{
        void onThumbnailDownload(T target,Bitmap thumbnail);
    }

    public void setThumbnailDownloadListener(ThumbnailDownloadListener<T> thumbnailDownloadListener) {
        mThumbnailDownloadListener = thumbnailDownloadListener;
    }

    public ThumbnailDownloader(Handler responseHandler){
        super(TAG);
        mResponseHandler=responseHandler;
    }

    @Override
    protected void onLooperPrepared() {
        mRequestHandler=new Handler(){
            @Override
            public void handleMessage(Message msg) {
                if (msg.what==MESSAGE_DOWNLOAD){
                    T target=(T)msg.obj;
                    Log.i(TAG,"Got a request for URL: "+mRequestMap.get(target));
                    handleRequest(target);
                }
            }
        };
    }

    @Override
    public boolean quit() {
        mHasQuit=true;
        return super.quit();
    }

    public void queueThumbnail(T target,String url){
        Log.i(TAG,"Got a URL: "+url);
        if (url==null){
            mRequestMap.remove(target);

        }else {
            mRequestMap.put(target,url);
            mRequestHandler.obtainMessage(MESSAGE_DOWNLOAD,target).sendToTarget();
        }
    }

    public void clearQueue(){
        mResponseHandler.removeMessages(MESSAGE_DOWNLOAD);
        mRequestMap.clear();
    }

    private void handleRequest(final T target){
        try{
            final String url=mRequestMap.get(target);
            if (url==null){
                return;
            }

            byte[] bitmapBytes=new FlickrFetchr().getUrlBytes(url);
            final Bitmap bitmap= BitmapFactory.decodeByteArray(bitmapBytes,0,bitmapBytes.length);
            Log.i(TAG,"Bitmap created");
            mResponseHandler.post(new Runnable() {
                @Override
                public void run() {
                    if (mRequestMap.get(target)!=url||mHasQuit){
                        return;
                    }

                    mRequestMap.remove(target);
                    mThumbnailDownloadListener.onThumbnailDownload(target,bitmap);
                }
            });
        }catch (IOException ioe){
            Log.e(TAG,"Error downloading image",ioe);
        }
    }
}
